A study of three-nucleon interaction in three- and four-body nuclei

Abstract

The variational Monte Carlo method is used to study the effect of model three-nucleon interactions on the binding energy and structure of 3He and 4He nuclei. Realistic two-nucleon intertions, such as Reid v 8 and Urbana v 14, as well as simple spin-isospin independent two-nucleon interactions such as the Malfliet-Tjon model V are used in this study. The three-nucleon interaction V ijk is assumed to depend on r ij , r ik and the angle θ i , of the triangle r i, r j and r k . It is shown that V ijk having P 2 (cos θ i ) angle dependence can explain the binding energy and the dip in the proton distribution of 3He nucleus. Results of limited studies of the effect of spin-isospin dependence of V ijk , are also presented. Simple models of V ijk , having only P 0 (cos θ i ) and P 2 (cos θ i ) terms can bring the theory of these nuclei closer to experiment, however they seem to give a much smaller dip in the proton distribution of 4He.